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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        //1.新增数组元素,修改length
        var arr = ['red', 'green', 'blue'];
        console.log(arr.length);
        arr.length = 5;
        console.log(arr.length);

        //2.新增数组元素,修改索引号,追加数组元素
        var arr1 = ['red', 'green', 'blue'];
        arr1[3] = 'pink';
        console.log(arr1);
        arr1.push('starbug');
        console.log(arr1);
    </script>
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